"The pipe fittings and 90° elbows were test fitted to see it would all fit together. I then made the retainer. This is a 2mm star shaped copper piece that has a small square soldered to the center. This will locate on the back, (top in a tower case), of the card the center square fits inside the resistors on the rear of the card opposite the GPU. Holes in the corners of both star” & GPU block (with a M2 thread tapped into block) accept M2 screws. I placed a small square of mica shim (inert thermal rubber shim), between the retaining star and the area of the card it will contact to prevent damage to the PCB or and copper to component contact."

FULL STORY @ DEVIANTPC(http://www.deviantpc.com/articles/gf4wcp3/index.shtml)